1. Technical Field
The present invention relates to plasma processing, and more specifically, to local plasma processing.
2. Related Art
In a typical semiconductor structure fabrication process, the deposition of a film on a wafer can frequently result in the film being thinner on the edge of the wafer than on other parts of the wafer (i.e., under-deposition at wafer edge). In addition, a chemical mechanical polishing (CMP) process performed on the wafer usually has a higher CMP rate at the edge of the wafer than at other parts of the wafer (i.e., over-polish at wafer edge). As a result, integrated circuits formed near the edge of the wafer may be damaged by this nonuniformity.
Therefore, there is a need for a method (and an apparatus for performing the method) to compensate for the problems of under-deposition and over-polish at the edge of a wafer.